Flooding in Afghanistan kills 32

Floods have swept through western Afghanistan, leaving 17 dead, and destroying over 500 homes.Image: AAP

Flash floods have killed at least 32 people in western Afghanistan, destroying homes and sweeping through makeshift shelters that housed displaced families.

Flooding caused by heavy rains started spreading on Thursday and left a trail of devastation across seven provinces, Afghanistan's National Disaster Management Authority spokesman Hasibullah Shir Khani said.

Another 12 people were missing and more than 700 houses were destroyed or severely damaged, he added.

The floods worsen an already desperate situation. Hundreds of thousands of people were displaced in the region by last year's severe drought and the 17-year-long war with the Taliban.

Floods in early March caused further destruction and put this year's wheat harvest at risk.

Shir Ahmad, who lives in Herat province, said his house and farmland had been destroyed.

"If you go and see the destruction it makes you cry," he said.

Floods are a common occurrence in Afghanistan, although not usually this severe. The country has little infrastructure, such as ditches and sewers, to manage water run-off from rain or melting snow.

World Vision said it appeared tens of thousands of Afghans were affected. Some residents of Badghis province were calling it the worst storm in 20 years, it said.